.div1,.div2,.div3,.div4,.div5,.div6{
    width: 100px;
    height: 100px;
    margin: 50px;
    background-color: red;
}
.div7,.div8{
    width: 100px;
    height: 200px;
    border: 50px solid #cd0000;
    margin: 50px;
}
.div1{
    border-radius: 50px;
}
.div2{
    /*设置左上角右下角为0   ,右上角-左下角为50*/
    border-radius: 0 50px;
}
.div3{
    /*设置左上角为50,右上角0 右下角50  左下角0*/
   border-radius: 50px 0 50px;
}
.div4{
    border-radius: 50px 0 50px 20px;
}
